Buy the Sony Vaio P500

Sony Vaio P500 Alternatives

Based on weight, screen-size and form-factor.

HP Slate 2, 8.9 inch, 690 grams (1.52 lbs)The HP Slate 2 is a Windows 7 Tablet powered by an Intel Atom Z670 clocked at 1.5 GHz. It has up to 64GB mSATA Storage and should last with its 2-cell (30WHr) battery up to 7.5 hours.
With the possibility to add the Tablet to the optional dock one can have 2 more USB 2.0 ports plus the ability to extend the screen via HDMI to another device.